Is it possible that recursively two calls to poll functions, both with `ms < 0`, are made? Would the caller not expect a result for the second call?

A call graph for this scenario (no input made):
```
os_inchar(...,ms=-1,...) -> 
inbuf_poll(-1) -> 
resize (results in a second blocking *_poll call) -> 
os_inchar(...,ms=-1,...) -> 
inbuf_poll(-1) -> 
read_from_input_buf() -> 
fill_input_buf(exit_on_error) -> 
read_error_exit()
```